The mobility of disabled persons has been increasing in recent years to include not only social and business life, but travel as well. Where once a disabled individual was expected to restrict travel away from home, today these special people are travelling around the world to conduct business or to vacation. Generally, this need for travel mobility felt by the disabled has been frustrated due to the lack of proper facilities and equipment aboard transportation vehicles. Over the years seat cost per mile has become paramount in the financial success of transportation companies and has increasingly dictated the size and shape of passenger vehicle interiors. Hence, narrow aisles, small lavatories, small stowage areas, and restricted use of transportation vehicle facilities have limited travel by the disabled communities.
As noted hereinabove, the aisles in transportation vehicles such as passenger aircraft, trains, buses, ships and the like are normally very narrow. Moreover, in vehicles such as these, stowage space is typically at a premium. Thus stowage space required to store items such as foldable wheelchairs is also at a premium. Ideally, such folding wheelchairs should be lightweight, should be of a size readily operable within narrow aisles, should be easy to fold and unfold in limited space working areas, and should fold into as narrow and compact a unit as possible.
Several designs for folding wheelchairs have been offered for use by the disabled which generally suffer from one or more disadvantages vis-a-vis transportation vehicle use. Examples of such devices are U.S. Pat. Nos. 3,666,292, 4,025,088, 4,076,304, and 4,164,354. The wheelchairs disclosed in these patents generally involve somewhat heavy and complex designs which include but are not limited to chair propelling and rotatable pivot type folding mechanisms (U.S. Pat. No. 3,662,292), multiple element collapsible X-frames U.S. Pat. No. (4,025,088), and single element X-frames (U.S. Pat. No. 4,164,354). In the case of U.S. Pat. No. 4,076,304 a rather complex slide-type folding system is disclosed which includes a linkage pinned at both ends, the center pivots being attached to a slide block which travels on a tube element to fold and unfold the wheelchair.
Other prior art carriers which utilize slide or linear translation type closure mechanisms are depicted in U.S. Pat. Nos. 2,629,607 and 2,639,162. U.S. Pat. No. 2,629,607 discloses a luggage carrier which utilizes a single level linkage having three sets of linkage elements pinned to a center bar. One of the three sets of linkages slides on the bar when the carrier is folded and unfolded. U.S. Pat. No. 2,639,162 is directed to yet another carriage which utilizes a center bar element and four sets of linkages. In this instance, one set of linkages, rather than sliding along the center bar, is attached to a telescoping tube within the center bar.
All of the above prior art patents, whether directed to wheelchairs or other type carriers, utilize rather complex folding mechanisms which include a multiplicity of hinged and pivoted parts. They thus have a tendency to be heavier than might otherwise be necessary, and in many cases, are folded into a package which is larger than might otherwise be desirable. This latter characteristic or problem is a natural consequence of utilization of complex folding elements.
One wheelchair design which is particularly useful for use in transportation vehicles is disclosed in U.S. Pat. No. 4,266,305, assigned to the assignee herein. This particular design, while finding great utility in transportation vehicles having bench type toilets, nevertheless is somewhat more complex than is necessary in many other uses in transportation vehicles which do not involve transporting a disabled person to such a toilet.
In view of the desire for enhanced mobility systems for the disabled, especially the desire for compact, inexpensive and non-complex wheelchairs for use by the disabled when using limited space transportation vehicles, there is a need for a folding wheelchair which satisfies all these requirements.
Thus it is a primary object of this invention to provide a novel folding wheelchair which is particularly well adapted for use with transportation vehicles.
It is another object of the present invention to provide an inexpensive and relatively non-complex folding wheelchair that can be easily and rapidly unfolded and folded and that is particularly well adapted to be put away in small stowage areas when in the folded condition.